East Side Access, a plan by the MTA to link the Long Island Rail Road and Grand Central Terminal through caverns deep underground, was “highly recommended” for federal subsidies by the Bush administration this week. Opponents of part or all of the plan have argued, however, that it is dangerous and profligate.

As described by the Metropolitan Transportation Authority, the $6.3 billion project will be a boon for 160,000 commuters a day, as well as the East Side businesses for which they are employees or customers.

Chief among the complaints of the project’s opponents is a ventilation facility, planned for East 50th Street. They say it will be a ticking time bomb, with fuel tanks in the basement and a tower spewing tainted exhaust in a bustling neighborhood.

The only public hearing by the MTA and the Federal Transit Administration is scheduled for today. Concerned residents of the East Side had an opportunity to pose their questions to an MTA representative last week during a meeting of Community Board 5’s transportation committee. The board, which cautiously supports the East Side Access plan, has recommended that the MTA closely consider public concerns and an alternative plan, which opponents said not only would be safer but would save as much as $2 billion.

East Side Access calls for building a four-platform terminal 15 stories below Grand Central to accommodate eight tracks for the Long Island Railroad. The project will shave an estimated 30 to 40 minutes off the commuting time of Long Islanders who work on the East Side and must now transfer at Penn Station before making their way back east across town.

To provide a supply of fresh air to the two immense caverns deep beneath the terminal – the MTA says it would be the largest mined underground terminal ever built in America – plans call for building the ventilation tower on the south side of 50th, between Park and Madison avenues. That is an area ringed with buildings of historic interest, including St. Patrick’s Cathedral, Saks Fifth Avenue, and the Waldorf-Astoria hotel.

The facility would house ventilation intakes, exhausts, and fans and related equipment; a loading dock to allow trucks to enter for waste removal, and a freight elevator. Five low-rise buildings would be demolished to make way for the facility, which from the outside would resemble an office building with a glass-and-metal facade.

According to the MTA’s recently released environmental assessment, the proposed facility would not have any significant adverse impacts – a conclusion some East Side residents dispute.

Assemblyman Jonathan Bing said he supports the East Side Access concept but objects to some aspects of the plan, which he said are dangerous to commuters and East Side residents.

One issue that has neighbors worried is plans for the basement storage of two fuel tanks, each holding between 6,000 and 8,000 gallons, to power emergency generators. The fuel tanks evoke memories of the explosion that brought down 7 World Trade Center on September 11, Mr. Bing said.

“Whether it’s the target of a terrorist attack or natural disaster,” the legislator said, “it could burn a large portion of Midtown Manhattan.”

The MTA’s representative at last week’s meeting, Audrey Heffernan, pointed out that many buildings throughout the city, including several in the area of the proposed facility, have fuel tanks in their basements, and she said the MTA has much more stringent safety measures than those in force at some of those buildings. In addition, she said, the facility’s fuel tanks will be stored deep in bedrock.

Aside from the specter of the entire East Side’s being consumed by an inferno, Mr. Bing expressed concern about a less apocalyptic scenario: health problems developing from exposure to the vent’s exhaust. Some East Side residents fear that the mist spewing from the ventilation tower will become contaminated with Legionnaire’s-type bacteria or, in the case of a terrorist attack, even more lethal material.

According to the MTA, however, water will be circulated and treated before it is emitted, to prevent such contamination. Further, representatives of the transportation authority said that the exhaust would consist only of ambient air vented from the terminal, which would be free of pollutants, and that the elevated air-intake system, within a building that it will own and operate, would increase protection of the station’s air supply against terrorism.

Among the plan’s opponents is Cardinal Edward Egan, who is wary of the tower’s proximity to the city’s most famous religious institution.

“We are concerned about it because it is very close to St. Patrick’s Cathedral,” the communications director for the Catholic Archdiocese of New York, Joseph Zwilling, told The New York Sun. “We have been in ongoing touch with the governor’s office to express concerns about it, and we will continue to do that.”

In light of environmental and safety concerns, not to mention the MTA’s budget woes, opponents of the plan are pushing for adoption of an option called the Upper Level Loop Alternative. It would route LIRR trains onto existing Metro North tracks into Grand Central, avoiding the perceived perils of having a concourse buried deep below Park Avenue, while saving billions of dollars.

Ms. Heffernan called the alternative “fatally flawed,” saying the loop option would cut service to Metro North by 50% during the extended construction period and by 30% when both systems are working at full capacity.

“I don’t know why you would want to save a few billions of dollars to build a transportation system that on the first day is overcrowded and cuts service to Metro North,” Ms. Heffernan said at last week’s community meeting.

A serious look into the Upper Level Loop Alternative would require a new environmental impact study, Ms. Heffernan said, which would lead to a three-year delay, resulting in the “same cost for a far inferior service.”

Another concern expressed by East Side residents is whether the proposed $16.8 billion Second Avenue subway line will be completed before East Side Access. If not, they worry that the influx of LIRR commuters would aggravate overcrowding of the Lexington Avenue subway line. The first phase of the Second Avenue subway project, a segment from 96th Street south that would connect to the Sixth Avenue line at E. 63rd Street, is expected by 2012 and has a price tag of $3.8 billion.

“If you bring in East Side Access to Grand Central, it will place a tremendous burden on what is already the most crowded form of transportation in the country, the Lexington Avenue line,” Mr. Bing said. “Without putting comparable funding for the Second Avenue line, it will make overcrowding even worse.”

Although the LIRR-Grand Central connection is also scheduled for completion by 2012, many wonder if that goal can be reached, as the MTA struggles for funds.

Governor Pataki, in releasing his budget last month, called for an allocation of $19.2 billion for the MTA over the next five years, $8.5 billion less than requested. A significantly reduced capital budget, MTA officials have said, would make it extremely difficult to do anything beyond maintaining the current mass-transit system.

East Side Access and the Second Avenue subway both got a boost this week when the Federal Transit Administration made the two Manhattan mass-transit projects the only ones out of 27 nationwide that it labeled “highly recommended.”

“It’s a great vote of confidence for this project,” Rep. Peter King, a Long Island Republican who supports East Side Access, said.

The federal agency has proposed spending $390 million on East Side Access in fiscal 2006. Paul Griffo, a spokesman for the agency, told the Sun yesterday that congressional approval was likely.

Ultimately, the federal government is expected to pitch in a total of $2.6 billion for East Side Access, with the MTA financing the remainder. On other projects, Mr. Griffo said, when state money is not available on schedule or projects go over budget, his agency seeks to guide the work back on track.

“We put on the brakes. We’ll say, we need to see a plan to get you back on course here,” he said. “But the FTA is satisfied that the MTA has demonstrated its ability to fulfill their end.”

Today’s public hearing is being held at MTA headquarters, 347 Madison Ave. Doors open at 5 p.m.

Assemblyman Bing said the MTA has a history of holding public hearings even though its officials have “already made up their minds.”

“But,” he said, “we want them to know that the people who live and work in this area really don’t think this is a good idea.”

The period for written public comment on East Side Access ends on February 22.